A coffee to harm the ozone

BRITAIN: The recovery of the ozone layer could be delayed until the end of the century because of the uncontrolled increase in emissions of an industrial chemical also used to decaffeinate coffee, a study has found.

The ozone layer floats about 25 kilometres above Earth, protecting it from ultraviolet radiation, which causes skin cancer and inhibits plant growth.

It has been slowly recovering since restrictions were imposed under the 1987 Montreal Protocol on chlorofluorocarbons (CFCs), used in aerosols and fridges.

The protocol did not address the damage done to the ozone layer by dichloromethane (DCM), a gas used in many industrial processes as well as decaffeination. CFCs were seen as the priority as they linger in the atmosphere for decades, unlike DCM, which breaks down in months.

However, the level of DCM in the atmosphere has more than doubled since 2000, according to research by Lancaster University in England.

If it continues to accumulate at the current rate, the recovery of the ozone hole over Antarctica, previously forecast for 2065, would be delayed by 30 years to 2095.

India and other parts of Asia are among the highest emitters of DCM, which is used as a cheap solvent and found in degreasers and paint strippers.

Ryan Hossaini, lead author of the study, said alternatives to DCM were available and more were being developed. Imposing restrictions on DCM would result in a rapid reduction in ozone damage because it was so short-lived, he added.

‘‘You could potentially remove it from the atmosphere quickly if emissions were curbed, in contrast to CFCs which have lifetimes of decades to centuries,’’ Hossaini said. – The Times